1. Exit teamviewer
2. Search "TeamViewer" in C:\Documents and Settings and delete all results
3. start -> regedit -> navigate to HKEY_CURENT_USER\Software\ and delete Teamviewer folder
4. start -> regedit -> navigate to HKEY_LOCAL_MACHINE\Software\ and delete Teamviewer folder
Change MAC address:
5. start -> run -> cmd -> "ipconfig /all"
copy the Physical Address, e.g: 00-C0-95-EC-B7-93 etc.
6. Right click on My Network Places -> properties -> right click on Local Area Connection -> properties -> Configure -> Advanced -> Network Address -> Paste in the address you copied above without "-", e.g: 00C095ECB793 and change a little bit, e.g 00C095ECB794
Restart and reinstall teamviewer, you'll have NEW ID